Flip chip packaging is the process of connecting a semiconductor die to a package, such as a leadframe or a substrate, without the use of wire bonds. In general, numerous conductive bumps are placed on an upper surface of the semiconductor die, and the die is then flipped over and placed on the package. The conductive bumps are typically formed using solder or conductive epoxy and are 70-100 μm high and 100-125 μm in diameter. With the emergence of Gallium Arsenide (GaAs) devices, the size and pitch of solder bumps prohibit the use of solder with GaAs devices. Further, due to the pitch of solder bumps, contact with the die and substrate are not maximized and results in less than maximum heat transfer. Conductive epoxy traps heat in the semiconductor die, thereby increasing the temperature gradient of the device and decreasing the efficiency of the device.
Thus, there remains a need for an improved means for attaching a GaAs die to a package.